FIG 3.

Repeated substitutions in key regions of Env unique to eCD4-Ig-selected swarms. Env mutations present in several individual isolates, not found in control swarms, are indicated. Sequences from the SHIV-SF162P3 reference sequence found in the apex region (residues 168 to 171), the base of V3 (residues 296 to 306), V4 (residues 382 to 390), and the CD4-binding site (residues 425 to 432) are shown. Changes from this reference sequence are shown, along with the number of independent wells in which a given pattern was observed. Note that K171E and Q428K emerged independently in several wells in combination with a mutation in the V3 base.